Browsing by Author "Department of Psychology, School of Science"
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Item Acute Cannabinoids Produce Robust Anxiety-Like and Locomotor Effects in Mice, but Long-Term Consequences Are Age- and Sex-Dependent(Frontiers Media, 2019-02-20) Kasten, Chelsea R.; Zhang, Yanping; Boehm, Stephen L., II; Department of Psychology, School of ScienceThe rise in cannabinoid legalization and decriminalization in the US has been paired with an increase in adolescents that perceive marijuana as a "no risk" drug. However, a comprehensive review of human literature indicates that cannabinoid usage may have both beneficial and detrimental effects, with adolescent exposure being a critical window for harming cognitive development. Although the cannabinoids Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) are often used together for recreational and medical purposes, no study has previously observed the acute and long-lasting effects of THC+CBD in a battery of behavioral assays analogous to subjective human reports. The current study observed the acute and long-term effects of THC, CBD, and THC+CBD on object recognition memory, anxiety-like behavior, and activity levels in adolescent and adult mice of both sexes. Acute THC alone and in combination with CBD resulted in robust effects on anxiety-like and locomotor behavior. A history of repeated cannabinoid treatment followed by a period without drug administration resulted in minimal effects in these behavioral assays. Most notably, the strongest effects of repeated cannabinoid treatment were seen in adult females administered THC+CBD, which significantly impaired their object recognition. No effects of repeated cannabinoid history were present on hippocampal protein expression. These studies represent a detailed examination of age- and sex-effects of acute and repeated cannabinoid administration. However, the acute and long-term effects of THC with and without CBD on additional behaviors in adolescents and adults will need to be examined for a more complete picture of these drug effects.Item Additional Support for the Cognitive Model of Schizophrenia: Evidence of Elevated Defeatist Beliefs in Schizotypy(Elsevier, 2016-07) Luther, Lauren; Salyers, Michelle P.; Firmin, Ruth L.; Marggraf, Matthew P.; Davis, Beshaun; Minor, Kyle S.; Department of Psychology, School of ScienceObjectives The cognitive model of poor functioning in schizophrenia posits that defeatist performance beliefs—overgeneralized negative beliefs about one's ability to perform tasks—develop prior to the onset of psychosis and contribute to the development and maintenance of negative symptoms and poor functioning. Although several studies with schizophrenia samples have provided support for the model, there is a paucity of research investigating these beliefs in individuals with schizotypy—those exhibiting traits reflecting a putative genetic liability for schizophrenia. This study had two aims: to examine whether defeatist performance beliefs (1) are elevated in schizotypy compared to controls and (2) are associated with decreased quality of life and working memory and increased negative but not positive schizotypy traits in the schizotypy group. Methods Schizotypy (n = 48) and control (n = 53) groups completed measures of schizotypy traits, defeatist performance beliefs, quality of life, and working memory. Results Analyses revealed that the schizotypy group reported significantly more defeatist performance beliefs than the control group. Within the schizotypy group, increased defeatist performance beliefs were significantly associated with greater negative schizotypy traits and lower quality of life. No significant associations were observed between defeatist performance beliefs and positive schizotypy traits and working memory. Conclusions Results generally support the theoretical validity of the cognitive model of poor functioning in schizophrenia and suggest that elevated defeatist performance beliefs may contribute to the manifestation of subclinical negative symptom traits and reduced quality of life among those with a latent vulnerability for schizophrenia.Item Adenosinergic regulation of binge-like ethanol drinking and associated locomotor effects in male C57BL/6J mice(Elsevier, 2015-08) Fritz, Brandon M.; Boehm II, Stephen L.; Department of Psychology, School of ScienceWe recently observed that the addition of caffeine (a nonselective adenosine receptor antagonist) to a 20% ethanol solution significantly altered the intoxication profile of male C57BL/6J (B6) mice induced by voluntary binge-like consumption in the 'Drinking-in-the-Dark' (DID) paradigm. In the current study, the roles of A1 and A2A adenosine receptor subtypes, specifically, in binge-like ethanol consumption and associated locomotor effects were explored. Adult male B6 mice (PND 60-70) were allowed to consume 20% ethanol (v/v) or 2% sucrose (w/v) for 6days via DID. On day 7, mice received a systemic administration (i.p.) of the A1 antagonist DPCPX (1, 3, 6mg/kg), the A2A antagonist MSX-3 (1, 2, 4mg/kg), or vehicle immediately prior to fluid access in DID. Antagonism of the A1 receptor via DPCPX was found to dose-dependently decrease binge-like ethanol intake and associated blood ethanol concentrations (p's<0.05), although no effect was observed on sucrose intake. Antagonism of A2A had no effect on ethanol or sucrose consumption, however, MSX-3 elicited robust locomotor stimulation in mice consuming either solution (p's<0.05). Together, these findings suggest unique roles for the A1 and A2A adenosine receptor subtypes in binge-like ethanol intake and its associated locomotor effects.Item Affective Systems Induce Formal Thought Disorder in Early-Stage Psychosis(APA, 2016-05) Minor, Kyle S.; Marggraf, Matthew P.; Davis, Beshaun J.; Mehdiyoun, Nicole F.; Breier, Alan; Department of Psychology, School of ScienceAlthough formal thought disorder (FTD) has been described since early conceptualizations of psychosis, its underlying mechanisms are unclear. Evidence suggests FTD may be influenced by affective and cognitive systems; however, few have examined these relationships—with none focusing on early-stage psychosis (EP). In this study, positive FTD and speech production were measured in sex- and race-matched EP (n = 19) and healthy control (n = 19) groups by assessing “reactivity”—a change in experimental compared with baseline conditions—across baseline, affective, and cognitive conditions. Relationships with functioning were also examined within each group. Three key findings emerged: (a) the EP group displayed large differences in positive FTD and speech production, (b) those with EP exhibited affective reactivity for positive FTD, and (c) positive FTD and affective reactivity were linked with poor real-world functioning in EP and these relationships did not considerably change when controlling for positive symptom (e.g., delusions, hallucinations) severity. Our findings provide preliminary evidence that affective, but not cognitive, systems play a critical role in positive FTD. Affective reactivity, in particular, may aid in predicting those with EP who go on to develop serious social impairments. Future work should focus on whether affective systems differentially influence those at separate points on the psychosis-spectrum in an effort to establish evidence-based treatments for FTD.Item African American patients' intent to screen for colorectal cancer: Do cultural factors, health literacy, knowledge, age and gender matter?(Johns Hopkins University Press, 2016-02) Brittain, Kelly; Christy, Shannon M.; Rawl, Susan M.; Department of Psychology, School of ScienceAfrican Americans have higher colorectal cancer (CRC) mortality rates. Research suggests that CRC screening interventions targeting African Americans be based upon cultural dimensions. Secondary analysis of data from African-Americans who were not up-to-date with CRC screening (n=817) was conducted to examine: 1) relationships among cultural factors (i.e., provider trust, cancer fatalism, health temporal orientation (HTO)), health literacy, and CRC knowledge; 2) age and gender differences; and 3) relationships among the variables and CRC screening intention. Provider trust, fatalism, HTO, health literacy and CRC knowledge had significant relationships among study variables. The FOBT intention model explained 43% of the variance with age and gender being significant predictors. The colonoscopy intention model explained 41% of the variance with gender being a significant predictor. Results suggest that when developing CRC interventions for African Americans, addressing cultural factors remain important, but particular attention should be given to the age and gender of the patient.Item African American Patients’ Intent to Screen for Colorectal Cancer: Do Cultural Factors, Health Literacy, Knowledge, Age and Gender Matter?(2016-02) Brittain, Kelly; Christy, Shannon M.; Rawl, Susan M.; Department of Psychology, School of ScienceAfrican Americans have higher colorectal cancer (CRC) mortality rates compared with all racial/ethnic groups. Research suggests that CRC screening interventions for African Americans target cultural variables. Secondary analysis of data from 817 African-Americans who had not been screened for CRC was conducted to examine: 1) relationships among cultural variables (provider trust, cancer fatalism, health temporal orientation [HTO]), health literacy, and CRC knowledge; 2) age and gender differences; and 3) relationships among cultural variables, health literacy, CRC knowledge, and CRC screening intention. Provider trust, fatalism, HTO, health literacy, and CRC knowledge demonstrated significant relationships among study variables. Stool blood test intention model explained 43% of the variance, with age and gender being significant predictors. Colonoscopy intention model explained 41% of the variance with gender a significant predictor. Results suggest when developing CRC interventions for African Americans, addressing cultural variables is important, but particular attention should be given to age and gender.Item Age and Impulsive Behavior in Drug Addiction: A Review of Past Research and Future(Elsevier, 2018-01) Argyriou, Evangelia; Um, Miji; Carron, Claire; Cyders, Melissa A.; Department of Psychology, School of ScienceImpulsive behavior is implicated in the initiation, maintenance, and relapse of drug-seeking behaviors involved in drug addiction. Research shows that changes in impulsive behavior across the lifespan contribute to drug use and addiction. The goal of this review is to examine existing research on the relationship between impulsive behavior and drug use across the lifespan and to recommend directions for future research. Three domains of impulsive behavior are explored in this review: impulsive behavior-related personality traits, delay discounting, and prepotent response inhibition. First, we present previous research on these three domains of impulsive behavior and drug use across developmental stages. Then, we discuss how changes in impulsive behavior across the lifespan are implicated in the progression of drug use and addiction. Finally, we discuss the relatively limited attention given to middle-to-older adults in the current literature, consider the validity of the measures used to assess impulsive behavior in middle-to-older adulthood, and suggest recommendations for future research.Item Amphetamine Exerts Dose-Dependent Changes in Prefrontal Cortex Attractor Dynamics during Working Memory(J. Neurosci, 2015-07-15) Lapish, Christopher C.; Balaguer-Ballester, Emili; Seamans, Jeremy K.; Phillips, Anthony G.; Durstewitz, Daniel; Department of Psychology, School of ScienceModulation of neural activity by monoamine neurotransmitters is thought to play an essential role in shaping computational neurodynamics in the neocortex, especially in prefrontal regions. Computational theories propose that monoamines may exert bidirectional (concentration-dependent) effects on cognition by altering prefrontal cortical attractor dynamics according to an inverted U-shaped function. To date, this hypothesis has not been addressed directly, in part because of the absence of appropriate statistical methods required to assess attractor-like behavior in vivo. The present study used a combination of advanced multivariate statistical, time series analysis, and machine learning methods to assess dynamic changes in network activity from multiple single-unit recordings from the medial prefrontal cortex (mPFC) of rats while the animals performed a foraging task guided by working memory after pretreatment with different doses of d-amphetamine (AMPH), which increases monoamine efflux in the mPFC. A dose-dependent, bidirectional effect of AMPH on neural dynamics in the mPFC was observed. Specifically, a 1.0 mg/kg dose of AMPH accentuated separation between task-epoch-specific population states and convergence toward these states. In contrast, a 3.3 mg/kg dose diminished separation and convergence toward task-epoch-specific population states, which was paralleled by deficits in cognitive performance. These results support the computationally derived hypothesis that moderate increases in monoamine efflux would enhance attractor stability, whereas high frontal monoamine levels would severely diminish it. Furthermore, they are consistent with the proposed inverted U-shaped and concentration-dependent modulation of cortical efficiency by monoamines.Item Assessment of the Influence of Demographic and Professional Characteristics on Health Care Providers' Pain Management Decisions Using Virtual Humans(2016-05) Boissoneault, Jeff; Mundt, Jennifer M.; Bartley, Emily J.; Wandner, Laura D.; Hirsh, Adam T.; Robinson, Michael E.; Department of Psychology, School of ScienceDisparities in health care associated with patients’ gender, race, and age are well documented. Previous studies using virtual human (VH) technology have demonstrated that provider characteristics may play an important role in pain management decisions. However, these studies have largely emphasized group differences. The aims of this study were to examine dentists’ and physicians’ use of VH characteristics when making clinical judgments (i.e., cue use) and to identify provider characteristics associated with the magnitude of the impact of these cues (β-weights). Providers (N=152; 76 physicians, 76 dentists) viewed video vignettes of VH patients varying in gender (male/female), race (white/black), and age (younger/older). Participants rated VH patients’ pain intensity and unpleasantness and then rated their own likelihood of administering non-opioid and opioid analgesics. Compared to physicians, dentists had significantly lower β-weights associated with VH age cues for all ratings (p<0.001; d>0.69). These effects varied by provider race and gender. For pain intensity, professional differences were present only among non-white providers. White providers had greater β-weights than non-white providers for pain unpleasantness but only among men. Provider differences regarding the use of VH age cues in non-opioid analgesic administration were present among all providers except non-white males. These findings highlight the interaction of patient and provider factors in driving clinical decision making. Although profession was related to use of VH age cues in pain-related clinical judgments, this relationship was modified by providers’ personal characteristics. Additional research is needed to understand what aspects of professional training or practice may account for differences between physicians and dentists and what forms of continuing education may help to mitigate the disparities.Item Avoidant Coping and Self-efficacy Mediate Relationships between Perceived Social Constraints and Symptoms among Long-term Breast Cancer Survivors(Wiley, 2016) Adams, Rebecca N.; Mosher, Catherine E.; Cohee, Andrea A.; Stump, Timothy E.; Monahan, Patrick O.; Sledge, George W., Jr; Cella, David; Champion, Victoria L.; Department of Psychology, School of ScienceObjective Many breast cancer survivors feel constrained in discussing their cancer experience with others. Limited evidence suggests that social constraints (e.g., avoidance and criticism) from loved ones may negatively impact breast cancer survivors' global health, but research has yet to examine relationships between social constraints and common physical symptoms. Informed by social cognitive processing theory, this study examined whether perceived social constraints from partners and healthcare providers (HCPs) were associated with fatigue, sleep disturbance, and attentional functioning among long-term breast cancer survivors (N = 1052). In addition, avoidant coping and self-efficacy for symptom management were examined as potential mediators of these relationships. Methods Long-term breast cancer survivors (mean years since diagnosis = 6) completed questionnaires assessing social constraints from partners and HCPs, avoidant coping, self-efficacy for symptom management, and symptoms (i.e., fatigue, sleep disturbance, and attentional functioning). Structural equation modeling was used to evaluate the hypothesized relationships among variables in two models: one focused on social constraints from partners and one focused on social constraints from HCPs. Results Both models demonstrated good fit. Consistent with theory and prior research, greater social constraints from both partners and HCPs were associated with greater symptom burden (i.e., greater fatigue and sleep disturbance, poorer attentional functioning). In addition, all relationships were mediated by avoidant coping and self-efficacy for symptom management. Conclusions Findings are consistent with social cognitive processing theory and suggest that symptom management interventions may be enhanced by addressing the impact of social constraints from survivors' partners and HCPs on their coping and self-efficacy.